Answer: uncertainty about the ability of the issuer to make timely payments of interest and principal
Step-by-step explanation:
AAA refers to the highest possible rating which can be assigned to the bond of an issuer by the main credit rating agencies. It should be noted that AAA bonds possesses a high degree of creditworthiness.
An investor who commits a sizable portion of her portfolio to long-term AAA-rated bonds would be exposing herself to uncertainty about the ability of the issuer to make timely payments of interest and principal.